Clear deskto notifications in some way

I noticed that sometimes to many notifications can built up. This results for example in: `(dbus-error "org.freedesktop.Notifications.Error.ExcessNotificationGeneration" "Created too many similar notifications in quick succession")` It would be good if notifications would be removed once answered. One option would be to assume that if a room has received a reply that all notifications of that room should be cleared. That would require that a kind of reverse notification function would run that checks if there was a message send by the session user which then would trigger that notifications for that room would be cleared. The 2nd option that could work on top of that is to update per room notifications,make their body grow and update the title.